Currently, intelligent transportation and security check have been popularizing, and related concepts have become well known. In these fields, vehicle model identification has played a crucial role. In fact, there is no clear definition on the vehicle mode identification. This is caused by its wide application and the huge differences in its implementation environments, means and purposes. In general, an identification aimed to obtain unique information of a vehicle, e.g., a vehicle plate number identification system, is defined as “vehicle identification.” And, the “vehicle model identification” here refers to means and methods for identifying a specific model of a vehicle in a non-contact manner or passive observation. In the practical application, the vehicle model identification has different purposes, depending on different requirements. For example, traffic analysis in the intelligent transportation only needs to care about the number of vehicles and the approximate vehicle models. In an aspect such as market statistics, public security inspection, etc., vehicle brand is more important. In the security inspection field, it is more critical to identify an accurate factory model of a vehicle.
Although the vehicle model identification has been studied, it is impossible to accurately identify the factory model.